半导体PVD金属化
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Al Al Al
Al
Magnetron Sputtering
• • •
Strong magnet is placed under the materials to be deposited thus produce a magnetic field in addition to the DC electrical field; Under the Lorentz force, Hopping electros is trapped near to the target thus enhanced the ionization efficiency. Advantage: – high deposition rate ~ 1m/min for Al,(10 times higher) – reducing electron bombardment of Sub. – extending the operating vacuum range
• •
Stress property changes with pressure; The transition point depends on gas, sputtering mode, materials.
2007/7/27
Morphology
• Morphology is strongly dependent on the process condition, recipe setting and the pre-/post- treatment; • Grain grooving:
Sputtering of alloys
Sputtering of alloys is difference with single element, the key factors:
Stoichiometry Sputtering yield; Saturated vapor pressure; Atomic mass; Efficient collision radius; Pressure; Power; CTE, thermo-condutivity; Solid Solutibility; magnetic properties; others
Recipe/equipment paraห้องสมุดไป่ตู้eters
Pressure Vacuum; Heater temp, Sub. gas flow; Power
Cooling rate;
Target-sub spacing Target grain size/purity; 2nd phase/ texture of target Target lifetime Shield / magnet / parts assembly Thermal conductivity
•Resistivity NU -- Sub. temp., film thickness, film crystallographic structure, Vacuum, pressure, power, spacing
•Thickness NU -•Particles -pressure, spacing, target life time, power, Crystallographic, target grain size Shield assembly, target / flake arcing, seasoning, target redeposition target grain size, parts lifetime
Schematic of DC sputtering
-power
Ar
Ar + Ar + Ar +
Schematic of DC sputtering
-power
Ar
Al
Ar +
Al
Ar +
Al
Ar +
Al
Schematic of DC sputtering
-power
Ar +
Ar +
Ar +
Ar
S S 3 4 M 1 M 2 E1 ( E1 1 KeV) 4 2 ( M 1 M 2 ) Eb 3.56 1 Z1 Z 2 M 1 S n ( E ) 2 2 E ( E1 1 KeV) M M 2 b Z13 Z 23 1
* : a measure of the efficiency of momentum transfer in collision Sn(E) : stopping power
Reactive sputtering
- sputtering metallic target in the presence of a reactive gas - eq). mixed with in gas (Ar)
oxides – Al2O3, SiO2, Ta2O5 (O2) nitrides – TaN, TiN, Si3N4 (N2, NH3) carbides – TiC, WC, SiC (CH4, C2H4, C3H8)
Crystallographic effect – FCC ( Al, Cu)
Crystallographic effect- Al, Cu
Crystallographic effect –HCP ( Ti)
FCC
HCP
Pressure transition
D.W. Hoffman & J.A. Thornton, JVST, 20 355(1982)
•Etching capabilities --Sub. temp., cooling efficiency of target, vacuum, pressure, target 2nd phase, target lifetime •Micro-structure --Sub. temp./condition, vacuum, pressure, power, target 2nd phase, target lifetime, cooling rate
•Morphology--
Sub. temp., Sub. condition, vacuum, pressure, power, target 2nd phase, target lifetime, cooling rate
MD chart- AL alloy
510C 340C 125C ~5mT 250C
What we care about the sputtering?
Key index of film
Resistivity Resistivity NU Thickness NU Particles Etching capabilities Micro-structure Stress Reflectivity Stoichiometry We must to build a bridge here!
– The thicker of film, the higher temp, the higher power setting, the cleaner of substrate, the larger grain more severe the grain grooving;
• Hillock/whisker/voiding
MD chart -- Ti
250C <0C
• • • •
Substrate temp and argon pressure is the key to determine the final microstructure of film. For Ti（1660C is melting point): 200C ~ 0.6Tm; 340C ~ 0.7Tm; Zone T is significant for Ti; Similar chart exists for the dependence between bias power and pressure (Temp).
• • • • •
Substrate temp and argon pressure is the key to determine the final microstructure of film. For AlCu（600C is melting point): 250C ~ 0.6Tm; 340C ~ 0.7Tm; Zone T is small for Al; Similar chart exists for the dependence between bias power and pressure (Temp). Ti has its own MD chart
- a measure of the energy loss per unit length due to nuclear collision
2007/7/27
Noble metal has higher sputtering yield;
Sputtering process variables
A : compounds B : doping, alloys A : all N2 reacts with Ta film doped metal (e.g.Ta N0.01) atomic ratio of N to Ta increases as N2 pressure increase B : Compound formation an the metal target, plasma impedance is effectively lower in state B than in state A,since ioninduced secondary electron emission is much higher for compounds than for metals.
Al
Magnetron Sputtering
• • •
Strong magnet is placed under the materials to be deposited thus produce a magnetic field in addition to the DC electrical field; Under the Lorentz force, Hopping electros is trapped near to the target thus enhanced the ionization efficiency. Advantage: – high deposition rate ~ 1m/min for Al,(10 times higher) – reducing electron bombardment of Sub. – extending the operating vacuum range
• •
Stress property changes with pressure; The transition point depends on gas, sputtering mode, materials.
2007/7/27
Morphology
• Morphology is strongly dependent on the process condition, recipe setting and the pre-/post- treatment; • Grain grooving:
Sputtering of alloys
Sputtering of alloys is difference with single element, the key factors:
Stoichiometry Sputtering yield; Saturated vapor pressure; Atomic mass; Efficient collision radius; Pressure; Power; CTE, thermo-condutivity; Solid Solutibility; magnetic properties; others
Recipe/equipment paraห้องสมุดไป่ตู้eters
Pressure Vacuum; Heater temp, Sub. gas flow; Power
Cooling rate;
Target-sub spacing Target grain size/purity; 2nd phase/ texture of target Target lifetime Shield / magnet / parts assembly Thermal conductivity
•Resistivity NU -- Sub. temp., film thickness, film crystallographic structure, Vacuum, pressure, power, spacing
•Thickness NU -•Particles -pressure, spacing, target life time, power, Crystallographic, target grain size Shield assembly, target / flake arcing, seasoning, target redeposition target grain size, parts lifetime
Schematic of DC sputtering
-power
Ar
Ar + Ar + Ar +
Schematic of DC sputtering
-power
Ar
Al
Ar +
Al
Ar +
Al
Ar +
Al
Schematic of DC sputtering
-power
Ar +
Ar +
Ar +
Ar
S S 3 4 M 1 M 2 E1 ( E1 1 KeV) 4 2 ( M 1 M 2 ) Eb 3.56 1 Z1 Z 2 M 1 S n ( E ) 2 2 E ( E1 1 KeV) M M 2 b Z13 Z 23 1
* : a measure of the efficiency of momentum transfer in collision Sn(E) : stopping power
Reactive sputtering
- sputtering metallic target in the presence of a reactive gas - eq). mixed with in gas (Ar)
oxides – Al2O3, SiO2, Ta2O5 (O2) nitrides – TaN, TiN, Si3N4 (N2, NH3) carbides – TiC, WC, SiC (CH4, C2H4, C3H8)
Crystallographic effect – FCC ( Al, Cu)
Crystallographic effect- Al, Cu
Crystallographic effect –HCP ( Ti)
FCC
HCP
Pressure transition
D.W. Hoffman & J.A. Thornton, JVST, 20 355(1982)
•Etching capabilities --Sub. temp., cooling efficiency of target, vacuum, pressure, target 2nd phase, target lifetime •Micro-structure --Sub. temp./condition, vacuum, pressure, power, target 2nd phase, target lifetime, cooling rate
•Morphology--
Sub. temp., Sub. condition, vacuum, pressure, power, target 2nd phase, target lifetime, cooling rate
MD chart- AL alloy
510C 340C 125C ~5mT 250C
What we care about the sputtering?
Key index of film
Resistivity Resistivity NU Thickness NU Particles Etching capabilities Micro-structure Stress Reflectivity Stoichiometry We must to build a bridge here!
– The thicker of film, the higher temp, the higher power setting, the cleaner of substrate, the larger grain more severe the grain grooving;
• Hillock/whisker/voiding
MD chart -- Ti
250C <0C
• • • •
Substrate temp and argon pressure is the key to determine the final microstructure of film. For Ti（1660C is melting point): 200C ~ 0.6Tm; 340C ~ 0.7Tm; Zone T is significant for Ti; Similar chart exists for the dependence between bias power and pressure (Temp).
• • • • •
Substrate temp and argon pressure is the key to determine the final microstructure of film. For AlCu（600C is melting point): 250C ~ 0.6Tm; 340C ~ 0.7Tm; Zone T is small for Al; Similar chart exists for the dependence between bias power and pressure (Temp). Ti has its own MD chart
- a measure of the energy loss per unit length due to nuclear collision
2007/7/27
Noble metal has higher sputtering yield;
Sputtering process variables
A : compounds B : doping, alloys A : all N2 reacts with Ta film doped metal (e.g.Ta N0.01) atomic ratio of N to Ta increases as N2 pressure increase B : Compound formation an the metal target, plasma impedance is effectively lower in state B than in state A,since ioninduced secondary electron emission is much higher for compounds than for metals.
